Presser-foot lifting mechanism for sewing machines



P. HLEB July 23; 1935.

PRESSER FOOT LIFTING MECHANISM FOR SEWING MACHINES Filed Nov. 24, 1954 2 Sheets-Sheet 1 July 23, 1935. I P. HLEB 2,009,194

PRESSER FOOT LIFTING MECHANISM FOR SEWING MACHINES Filed Nov. 24, 1934 2 Sheets-Sheei 2 1 1929197 HZeb w bf'neom M W MW Patented July 23, 1935 UNITED STATES PATENT OFFHCE PRESSER-FOOT LIFTING MECHANISM FOR SEWING MACHINES Peter Hleb, Elizabeth, N. J., assignor to The Singer Manufacturing Company, Elizaheth, N. J., a corporation of New Jersey Application November 24, 1934, Serial No. 754,560

' 8 Claims. (01.112-239) This invention relates to presser-foot lifting Wall of the bore I5 and the other end engages the mechanisms for sewing machines and has for its capped upper end of the bushing Hi. By adjustobject to provide simple means effective at high ment of the bushing M, the downward pressure speeds of operation of a sewing machine for inexerted by the spring it upon the presser-bar l2 termittently lifting the presser-foot to an extent may be varied. I

requisite for conveniently shifting work for darn- Pivotally embracing the crank-pin 8 is the ing, embroidering and like operations. J sleeved end ll of an angular take-up lever 18 ex- The invention consists in the presser-foot liftndin f rwardly beyond the head 3 and P ing device hereinafter described in connection vided in its free end with a thread-fl 1 with the accompanying drawings, which illustermediate its ends, the take-up lever It has a trate a preferred embodiment oi the invention. DiVOtal Connection 259 W th a Vibratory ta e- D in the drawings, Fig. 1 i a, front nd elevalever-controlling member, in the form of an antion, partly in section, of the bracket-arm head (s i link 2! for t lever B. he hub-Sleeve of a sewing machine and of thework-supporting 22 of the link 2! is pivotally mounted upon a section of the bracket-arm head, substantially on i a ap 25 p v in t e c et-a m the line 2-2 of Fig. 1. Fig. 3 represents a horhead 3. Secured upon or integral with the hubizontal section of the bracket-arm head .on subsleeve 22 of the link 2| is a presser-bar lifterstantially the line 3 3 of Fig. 1. Fig. 4 reprecam 26 disposed adjac n to th pr rr cents a perspective view of the cam-engaged lug a d am having an ap t e in its end face secured upon the presser-bar. Fig. 5 represents to receive th head o the fulcrum-pin 3- a perspective view of the take up anchoring link Secured by a set-Sc ew 9 up the D provided with a presser-bar lifter cam. Fig. 6 is ar for vertical adjustment thereupon, is a a diagrammatic view illustrating a cycle of movea from W h extends a lug 353 v yinent or the needle-bar actuating and pressering the 0am The Spring It a to p s foot lifting mechanisms. the presser-bar l2 to an extent whereby the Referring to the drawings, a sewing machine under c of the 111g 36 i engaged by the 0am in which the present invention has been embodied a preferred adjusted position of the collar has a frame including a cylindrical work-sup being Such that the Dresser-foot i3 is held Slightj porting arm i and a hollow bracket-a1-m 2 ter- 1y above the. work-support in the lowest position minating in a head 3 overhanging the ork-supof the presser-foot. .With this arrangement, the porting rm, cam 26 is in constant wiping engagement with the Journaled for rotation in suitable bearings proa g It W be H Ge 'StOOd that for vided in the bracket-arm 2 is an actuating shaft e p p actuating the 0am e a of (3 provided, Within t head 3, ith t the take-up lever it which connects the crankbalanced crank-arm 5 carrying a crank-pin 6. p 5 t0 the p a y m r 2! 0011- The crank-pin 6 has an ofifset portion I pivotally stitutes, in effect, a link. connected by an auxiliary crank-pin to one end In Fig. 6 of the d w g A represents the of a link 8, of which the opposite end is pivotall position of the needle-reciprocating crank i when 40 connected to a collar 9 suitably secured upon a he need e is about to enter the work, and B vertically disposed needle-bar Iii. The needlerepresents a corresponding point in the vertical bar It is journaled for endwise reciprocation in path of movement of the needle-bar. The corresuitable bearings provided in the head 3 and carspending position of the take-up actuating crankries at its lower end a needle I I. pin 5 is represented as at C, the pivotal connec- Also vertically movable in the bracket-arm tion 26 of the take-up lever 8 with the anchoring head 3 is a presser-bar 52 carrying at its lower link2l as at D, whileE represents the correspondend a suitable presser-foot It, said presser-bar ing point in the vertical path of movement of the having its upper end journaled for endwise movepresser-bar l2. It may be here mentioned that ment in a bearingg bushing M threaded Vertically the travel of the point E is shown in an oval path iii while the lower end of the presser-bar passes stood of course that the presser-bar is confined through a suitable bearing aperture in the bottom to right line movements. Progressive points in wall of said head. The presser-bar I2 is prothe paths of movement of each of said elements vided with a longitudinal bore l5 receiving a are represented by the same letters but with conspring l6 of which one end engages the bottom secutively higher exponents. From the diagramarm thereof. Fig. 2 represents a central vertical horizontal fulcrum-pin 23 secur by a -S w 0 into the top wall of the bracket-arm head 3, merely for illustration purposes, it being undermatic illustration in Fig. 6 it will be readily understood that the presser-bar l2 descends Very rapidly from the time the needle enters the work until the needle approaches completion of its downward movement. The descending movement is now retarded and, in fact, is not completed until after the needle starts to rise. Furthermore, the initial Work-disengaging movement of the presser-foot is slow comparatively to the movement of retraction of the needle from the work, whereby there is produced the general effect of a dwell in the movement of the presser-foot until the needle is withdrawn from the work, which occurs when the crank l is substantially at A, the needle-bar at E the pivotal connection 20 at D and the presser-bar at E The presser-bar is thereafter rapidly lifted, while the needle is out of the work, to provide for manipulation of the work. In other words, the variable motion imparted to the vibratory member or anchoring link 2| lends itself favorably to the employment of a lifting cam having an easy lifting effect upon the presser-bar.

Having thus set forth the nature of the invention, what I claim herein is:-

1. In a sewing machine, a work-support, a presser-foot carrying bar movable toward and from said work-support and provided with a camengaged lug, a vibratory member, a cam carried by said vibratory member in operative engagement with said lug, a rotary shaft, an actuating element carried by said shaft, and a link connecting said actuating element to said vibratory member.

2. In a sewing machine, a work-support, a presser-foot carrying bar movable toward and from said Work-support and provided with a camengaged lug, a vibratory member having a hub fulcrumed adjacent to said presser-bar, a cam carried by the hub of said vibratory member in operative engagement with said lug, a rotary shaft, an actuating element carried by said shaft, and a link connecting said actuating element to said vibratory member.

3. In a sewing machine, an endwise reciprocatory presser-foot carrying bar provided with a cam-engaged lug, a vibratory member, a cam carried by said vibratory member, a spring acting to yieldingly hold said lug in engagement with said cam, a rotary shaft, an actuating element carried by said shaft, and a link connecting said actuating element to said vibratory member.

4. In a sewing machine, an endwise reciprocatory presser-foot carrying bar provided with a cam-engaged lug, a member fulcrumed for vibratory movements about an axis transverse to said presser-bar, a cam carried by said member, a spring yieldingly holding said lug in engagement with said cam, a rotary actuating shaft, a crank-arm carried by said shaft and provided with a crank-pin, and a link connecting said crank-pin and member.

5. In a sewing machine, a Work-support, a vertically movable presser-foot carrying bar, a collar secured for vertical adjustment upon said presser-bar and having a lug projecting laterally therefrom, a member fulcrumed adjacent to said presser-bar for vibratory movements about a substantially horizontal axis, a cam carried by said member and underlying said lug, a spring acting to yieldingly hold said lug in engagement with said cam, a horizontally disposed rotary shaft, an actuating element carried by said shaft, and a link connecting said actuating element to said member.

5. In a sewing machine, a reciprocatory needlecarrying bar, a presser-foot carrying bar, a takeup lever provided with a thread-eye, and take-up lever actuating means including a vibratory takeup lever controlling member, provided with presser-bar lifting means.

'7. In a sewing machine having a frame includ-- ing a work-support, a rotary actuating shaft, 2. reciprocatory needle-carrying bar, a presser-bar movable toward and from said work-support, a needle-thread take-up lever operatively connected to said rotary shaft, a link pivotally anchoring said take-up lever to said frame, and presserbar lifting means actuated by said link.

8. In a sewing machine having a frame including a work-support, a rotary actuating shaft, a reciprocatory needle-carrying bar, an endwise reciprocatory presser-foot carrying bar provided with a cam-engaged lug, a needle-thread take-up lever operatively connected to said rotary shaft, a link pivotally connected to said take-up lever and having a hub fulcrumed upon said frame, a presser-bar lifting cam carried by the hub of said link, and a spring acting to hold said lug in engagement with said cam.

PETER I-ILEB. 

